海气相互作用英文版

Courtesy of E. J. Walsh
Unresolved Problems in High Resolution: Wave-Property Dependent
ห้องสมุดไป่ตู้
Air-Sea Coupled Modeling Provides Potential Research Opportunities
• • • • • General parameterization of air-sea fluxes: high wind speeds and oceanic mixing Gas transfer: General theory for all gases, bubbles, direct measurements Linking to fundamental processes (wave breaking and spray/bubble generation) Near-surface observations in hurricanes Transition from Research to Operations
Surface Flux Parameterizations
Met Flux : < w' x' > = C xU ( X s − X r ) = C xUΔX
Mean air-sea interface
A parameterization of sea-spray effect on momentum and heat fluxes has been developed at NOAA/ESRL.
Surface Flux Parameterizations
Met Flux : < w' x' > = C xU ( X s − X r ) = C xUΔX
• U, Xs, and Xr are the surface wind, and the property x in the ocean and air • Cx is the key to the parameterization – contains all the information about the INTERFACE (including the fluxes themselves!!!) Cd -- drag coefficient Ck -- heat exchange coefficient
OUTLINE • Air-sea coupled modeling at high winds: a research subject • ESRL regional air-sea coupled model for storm simulations • Challenges of air-sea coupled modeling • Future potential in research
Some Exciting New Developments at ESRL
• New NOAA funds (!!?): DTC • New observing systems (W-band radar for P-3, buoy turbulence/spray) • Cooperation with NWS on Hurricane Weather Research Forecasting Model
Air-Sea Interaction: Multi-Scale Processes
From the CBLAST Homepage
Components of the ESRL Coupled Air-Sea Modeling System
Air-Sea Interaction at High Winds: Issues to Address
Droplet Effect in Fluxes at High Wind Speeds Sensible and latent heat fluxes: spray-size dependent
1) Thermal conduction and evaporation occur on different time scales. 2) Time scales of both are highly dependent on drop size. • Small droplets do not add to the total enthalpy flux, but cool and moisten the surface layer, and thus decrease hurricane intensity. • Large droplets increase the enthalpy flux, warm the surface layer, and increase hurricane intensity.
Air-Sea Coupled Modeling of Storms: Collaborative Research at ESRL
Jian-Wen Bao Chris Fairall Sara Michelson Laura Bianco Jim Wilczak Physical Science Division/ESRL Collaborators: Naomi Surgi (NOAA/NCEP/EMC) Lakshmi Kantha (University of Colorado) Shuyi Chen (University of Miami) Isaac Ginis (University of Rhode Island)
Black radials extend in the wave propagation direction with a distance proportional to the wavelength. Their width is proportional to the significant wave height. Wind contours at 5 m/s, and the color scale changes at 10 m/s intervals.
Droplet Effect in Fluxes at High Wind Speeds
Momentum flux: competing theories: • Spray is generated at the expense of the meanwind momentum, therefore reduces surface winds. •Spray is generated at the expense of turbulence kinetic energy, increases the surface layer stability, and thus increases surface winds by reducing the surface drag.
• Anomalous oceanic mixing associated with El Nino and landfalling winter storms • Air-Sea fluxes and hurricane intensity – Role of sea-spray on sensible and latent heat fluxes
Droplet Effect in Fluxes at High Wind Speeds
USATODAY.com
Sea spray whips winds to hurricane strength By Michelle Lefort, USA TODAY Posted 7/31/2005. In a study out last week, researchers from the University of California, Berkeley, and a Russian colleague argue that sea spray kicked up by storms actually has a lubricating effect that helps accelerate wind. Chorin says that sea spray reduces turbulence — chaotic fluctuations in wind velocity and direction — like a comb through unruly hair.
Simulation with GFDL Operational Model: Isabel
GFDL Model, spray-modified (green) surface fluxes: with and without sea spray
Unresolved Problems in High Resolution: Wave-Property Dependent